Program to left rotate the elements of an array

Q. Program to left rotate the elements of an array.

Explanation

In this program, we need to rotate the elements of an array towards the left by the specified number of times. In the left rotation, each element of the array will be shifted to its left by one position and the first element of the array will be added to end of the list. This process will be followed for a specified number of times.

Program to left rotate the elements of an array

Consider above array, if n is 1 then, all elements of the array will be moved to its left by one position such that second element of the array will take the first position, the third element will be moved to the second position and so on. The first element of the array will be added to the last of the array.

Algorithm

Declare and initialize an array.
Variable n will denote the number of times an array should be rotated toward its left.
The array can be left rotated by shifting its elements to a position prior to them which can be accomplished by looping through the array and perform the operation arr[j] = arr[j+1].
The first element of the array will be added to the last of rotated array.

Solution

Python

  #Initialize array   arr = [1, 2, 3, 4, 5];   #n determine the number of times an array should be rotated  n = 3;     #Displays original array  print(“Original array: “);  for i in range(0, len(arr)):      print(arr[i]),      #Rotate the given array by n times toward left  for i in range(0, n):      #Stores the first element of the array      first = arr[0];            for j in range(0, len(arr)-1):          #Shift element of array by one          arr[j] = arr[j+1];                #First element of array will be added to the end      arr[len(arr)-1] = first;     print();     #Displays resulting array after rotation  print(“Array after left rotation: “);  for i in range(0, len(arr)):      print(arr[i]),  

Output:

Original array:   1 2 3 4 5   Array after left rotation:   4 5 1 2 3

C

  #include <stdio.h>     int main()  {      //Initialize array       int arr[] = {1, 2, 3, 4, 5};       //Calculate length of array arr      int length = sizeof(arr)/sizeof(arr[0]);      //n determine the number of times an array should be rotated      int n = 3;            //Displays original array      printf(“Original array: n”);      for (int i = 0; i < length; i++) {           printf(“%d “, arr[i]);       }              //Rotate the given array by n times toward left      for(int i = 0; i < n; i++){          int j, first;          //Stores the first element of the array          first = arr[0];                for(j = 0; j < length-1; j++){              //Shift element of array by one              arr[j] = arr[j+1];          }          //First element of array will be added to the end          arr[j] = first;      }            printf(“n”);            //Displays resulting array after rotation      printf(“Array after left rotation: n”);      for(int i = 0; i < length; i++){          printf(“%d “, arr[i]);      }      return 0;  }  

Output:

Original array:   1 2 3 4 5   Array after left rotation:   4 5 1 2 3

JAVA

  class RotateLeft {          public static void main(String[] args) {                //Initialize array           int [] arr = new int [] {1, 2, 3, 4, 5};           //n determine the number of times an array should be rotated          int n = 3;                    //Displays original array          System.out.println(“Original array: “);          for (int i = 0; i < arr.length; i++) {               System.out.print(arr[i] + ” “);           }                      //Rotate the given array by n times toward left          for(int i = 0; i < n; i++){              int j, first;              //Stores the first element of the array              first = arr[0];                        for(j = 0; j < arr.length-1; j++){                  //Shift element of array by one                  arr[j] = arr[j+1];              }              //First element of array will be added to the end              arr[j] = first;          }                    System.out.println();                    //Displays resulting array after rotation          System.out.println(“Array after left rotation: “);          for(int i = 0; i< arr.length; i++){              System.out.print(arr[i] + ” “);          }      }  }  

Output:

Original array:   1 2 3 4 5   Array after left rotation:   4 5 1 2 3

C#

  using System;                        public class RotateLeft  {      public static void Main()      {          //Initialize array           int [] arr = new int [] {1, 2, 3, 4, 5};           //n determine the number of times an array should be rotated          int n = 3;                    //Displays original array          Console.WriteLine(“Original array: “);          for (int i = 0; i < arr.Length; i++) {               Console.Write(arr[i] + ” “);           }                      //Rotate the given array by n times toward left          for(int i = 0; i < n; i++){              int j, first;              //Stores the first element of the array              first = arr[0];                        for(j = 0; j < arr.Length-1; j++){                  //Shift element of array by one                  arr[j] = arr[j+1];              }              //First element of array will be added to the end              arr[j] = first;          }                    Console.WriteLine();                    //Displays resulting array after rotation          Console.WriteLine(“Array after left rotation: “);          for(int i = 0; i< arr.Length; i++){              Console.Write(arr[i] + ” “);          }      }  }  

Output:

Original array:   1 2 3 4 5   Array after left rotation:   4 5 1 2 3

PHP

  <!DOCTYPE html>  <html>  <body>  <?php  //Initialize array   $arr = array(1, 2, 3, 4, 5);   //n determine the number of times an array should be rotated  $n = 3;     //Displays original array  print(“Original array: <br>”);  for ($i = 0; $i < count($arr); $i++) {       print($arr[$i] . ” “);   }          //Rotate the given array by n times toward left  for ($i = 0; $i < $n; $i++){      //Stores the first element of the array      $first = $arr[0];            for($j = 0; $j < count($arr)-1; $j++){          //Shift element of array by one          $arr[$j] = $arr[$j+1];      }      //First element of array will be added to the end      $arr[$j] = $first;  }     print(“<br>”);     //Displays resulting array after rotation  print(“Array after left rotation: <br>”);  for ($i = 0; $i < count($arr); $i++) {       print($arr[$i] . ” “);   }      ?>  </body>  </html>  

Output:

Original array:   1 2 3 4 5   Array after left rotation:   4 5 1 2 3

Next Topic#

Q. Program to left rotate the elements of an array.

Explanation

Algorithm

Solution

Python

C

JAVA

C#

PHP

Wind Energy

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